[VOL-2235] Mocks and interfaces for rw-core
This update consists of mocks that are used by the rw-core
during unit testing. It also includes interfaces used for unit
tests.
Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/metric.go b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
new file mode 100644
index 0000000..55e6d86
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
@@ -0,0 +1,174 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+ "strings"
+ "time"
+
+ "github.com/golang/protobuf/proto"
+
+ dto "github.com/prometheus/client_model/go"
+)
+
+const separatorByte byte = 255
+
+// A Metric models a single sample value with its meta data being exported to
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
+type Metric interface {
+ // Desc returns the descriptor for the Metric. This method idempotently
+ // returns the same descriptor throughout the lifetime of the
+ // Metric. The returned descriptor is immutable by contract. A Metric
+ // unable to describe itself must return an invalid descriptor (created
+ // with NewInvalidDesc).
+ Desc() *Desc
+ // Write encodes the Metric into a "Metric" Protocol Buffer data
+ // transmission object.
+ //
+ // Metric implementations must observe concurrency safety as reads of
+ // this metric may occur at any time, and any blocking occurs at the
+ // expense of total performance of rendering all registered
+ // metrics. Ideally, Metric implementations should support concurrent
+ // readers.
+ //
+ // While populating dto.Metric, it is the responsibility of the
+ // implementation to ensure validity of the Metric protobuf (like valid
+ // UTF-8 strings or syntactically valid metric and label names). It is
+ // recommended to sort labels lexicographically. Callers of Write should
+ // still make sure of sorting if they depend on it.
+ Write(*dto.Metric) error
+ // TODO(beorn7): The original rationale of passing in a pre-allocated
+ // dto.Metric protobuf to save allocations has disappeared. The
+ // signature of this method should be changed to "Write() (*dto.Metric,
+ // error)".
+}
+
+// Opts bundles the options for creating most Metric types. Each metric
+// implementation XXX has its own XXXOpts type, but in most cases, it is just be
+// an alias of this type (which might change when the requirement arises.)
+//
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type Opts struct {
+ // Namespace, Subsystem, and Name are components of the fully-qualified
+ // name of the Metric (created by joining these components with
+ // "_"). Only Name is mandatory, the others merely help structuring the
+ // name. Note that the fully-qualified name of the metric must be a
+ // valid Prometheus metric name.
+ Namespace string
+ Subsystem string
+ Name string
+
+ // Help provides information about this metric.
+ //
+ // Metrics with the same fully-qualified name must have the same Help
+ // string.
+ Help string
+
+ // ConstLabels are used to attach fixed labels to this metric. Metrics
+ // with the same fully-qualified name must have the same label names in
+ // their ConstLabels.
+ //
+ // ConstLabels are only used rarely. In particular, do not use them to
+ // attach the same labels to all your metrics. Those use cases are
+ // better covered by target labels set by the scraping Prometheus
+ // server, or by one specific metric (e.g. a build_info or a
+ // machine_role metric). See also
+ // https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
+ ConstLabels Labels
+}
+
+// BuildFQName joins the given three name components by "_". Empty name
+// components are ignored. If the name parameter itself is empty, an empty
+// string is returned, no matter what. Metric implementations included in this
+// library use this function internally to generate the fully-qualified metric
+// name from the name component in their Opts. Users of the library will only
+// need this function if they implement their own Metric or instantiate a Desc
+// (with NewDesc) directly.
+func BuildFQName(namespace, subsystem, name string) string {
+ if name == "" {
+ return ""
+ }
+ switch {
+ case namespace != "" && subsystem != "":
+ return strings.Join([]string{namespace, subsystem, name}, "_")
+ case namespace != "":
+ return strings.Join([]string{namespace, name}, "_")
+ case subsystem != "":
+ return strings.Join([]string{subsystem, name}, "_")
+ }
+ return name
+}
+
+// labelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers.
+type labelPairSorter []*dto.LabelPair
+
+func (s labelPairSorter) Len() int {
+ return len(s)
+}
+
+func (s labelPairSorter) Swap(i, j int) {
+ s[i], s[j] = s[j], s[i]
+}
+
+func (s labelPairSorter) Less(i, j int) bool {
+ return s[i].GetName() < s[j].GetName()
+}
+
+type invalidMetric struct {
+ desc *Desc
+ err error
+}
+
+// NewInvalidMetric returns a metric whose Write method always returns the
+// provided error. It is useful if a Collector finds itself unable to collect
+// a metric and wishes to report an error to the registry.
+func NewInvalidMetric(desc *Desc, err error) Metric {
+ return &invalidMetric{desc, err}
+}
+
+func (m *invalidMetric) Desc() *Desc { return m.desc }
+
+func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
+
+type timestampedMetric struct {
+ Metric
+ t time.Time
+}
+
+func (m timestampedMetric) Write(pb *dto.Metric) error {
+ e := m.Metric.Write(pb)
+ pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
+ return e
+}
+
+// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
+// way that it has an explicit timestamp set to the provided Time. This is only
+// useful in rare cases as the timestamp of a Prometheus metric should usually
+// be set by the Prometheus server during scraping. Exceptions include mirroring
+// metrics with given timestamps from other metric
+// sources.
+//
+// NewMetricWithTimestamp works best with MustNewConstMetric,
+// MustNewConstHistogram, and MustNewConstSummary, see example.
+//
+// Currently, the exposition formats used by Prometheus are limited to
+// millisecond resolution. Thus, the provided time will be rounded down to the
+// next full millisecond value.
+func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
+ return timestampedMetric{Metric: m, t: t}
+}